Tool



Patented Oct. 23, 1945 T J TOOL Eugene T. Daubs, South St. Paul,

Application June 12, 1944, serialivojsaaseafl 1 30laims. (of. 254-131 "Thislinvention relates to tools and more particularly to a type of tool adapted to facilitate the removal of wrist-pins adapted to hold the pistons and connecting rods of gasoline engines L in related assembly:

j i I .A primary object of this invention is the pro hvisionyof a tool adapted to ease the tensional engagement of a portionof a connecting rod engaging aywrist-pin to hold the connecting rod and a, pistontin related assembly, whereby the wrist.

fpins and hence the crank shaft of a gasoline en- [glne may be readily disassembled.

r An additional object of thisinvention is the provision of atool adapted to facilitate the removal and replacement of such a wrist-pin withof the engine.

5 and durable in construction, and relatively sim out the necessity of removing the cylinder head *A still further object is the provision of such a tool which will be reliable in operation, sturdy ple and inexpensiveto manufacture.

As conducive to: aj-clearer understanding of this invention it may here be pointed out that in conventional gasoline engines the ends of the connecting rods are provided with wrist-pin clamps comprised of a circular portion adapted to surround the wristepin, and extending split lugs,

each having an aperture therethrough, one of -ujfwhich has a smooth bore and the other of which isl sthreaded, a screw being adapted to pass through the smooth bore and eng ethe thread- -ed bore and when tightened to hold the clamps tightly about the wrist-pin. The ends of the wrist pin are journaled for rotative movement in the side walls of the piston. As removal and replacement of the wrist-pins occurs very infrequently, perhaps no more than once in several years, it frequently happens that even after removal of the screw holding the clamp together the clamp has become set and retains a relatively tight grip on the wrist-pin, making removal thereof extremely difficult, unless the cylinder head is completely removed and the piston brought upwardly through the cylinder to a position wherein it may be driven outwith a hammer, forexample. A primary object of this invention, therefore, is the provision of a tool which will release the relatively tight engagement of the clamp on the connecting rod with the wristpin, unler such conditions, whereby the pin may Having reference now to the accompanying drawings wherein there is shown a preferred form of this inventive concept:

Figure 1 is a side' elevational view of one form of device of the instant invention shown in association with a piston and connecting rod, certain parts being broken away and certain other parts being shown in section." 1 p Figure 2 is a view similar to Figure 1 but showthe the operating parts of the tool in a different position of adjustment.

Figure 3 is a front elevational view of the to shown in Figures 1 and 2, and r Figure 4 is a detailed sectional view of certain of the operating parts of the mechanism.

Like reference numerals refer to like parts throughout the several views of the drawings.

Having reference now to the drawings, and more particularly to Figures 1 and 2, a connecting rod IU of conventional type has at its lower extremity a bifurcated portion ll forming a semi-cylindrical recess I2, adapted to engage a crankshaft (not shown). Extending from portion I I outwardly, are two projections l3 through which are passed vertical bores [4 adapted for the engagement of screws holding the conventional' lower clamp (not shown), to secure the connecting rod tothe crankshaft. The upper endof connecting rod Ill terminates in an enlarged portion [5 having a centrally disposed circular aperture l6 therethrough adapted to surround a'wrist-pin H. The outer ends of wristpin H are journaled, in the conventional manner, in the side walls of a piston l8. Portion l5 is splitas at l9, and has extending from opposite sides of the split portion a pair of projecting lugs 2'0 and 2|, each of which has an aperture therethrough. The aperture 22 in lug 2| is smooth, while the aperture 23 in lug 20 is threaded. Thus the passage of a headed screw through aperture 22 into threaded engagement with aperture 23 and tightening of the same will result in a clamping action holding the connecting rod in and wrist-pin ll securely in related assembly.

The mechanism hereinbefore described is all conventional and has been described merely to show the operating parts upon which the tool of the instant invention acts.

Having reference now to the tool, generally indicated at 25, comprising the instant invention, a bar preferably cylindrical in configuration and of a suitable metal, is formed to provide a handle portion 26, bent inwardly as at 21, bent upwardly as at 28, and bent outwardly in a slight curve as at 29. The upper outwardly curved portion 29 terminates in a flat or ball-shaped portion 30 of a diameter adapted to pass through smooth bored aperture 22 but insufficient to pass through threaded aperture 23 and hence adapted under conditions to be hereinafter described to seat itself in the mouth of threaded aperture 23.

A member generally indicated at 35 comprised of a cylindrical body portion 36 (see Figure 4), and bifurcated at its upper extremity to provide a pair of extending legs 31 and 38 (see Figure 3), is pivotally secured to portion 21 of rod 25 as by means of a rivet 39 passed through suitable apertures in legs 31 and 38 and portion 21. The lower portion of member 35 is provided with a threaded aperture therein, adapted to engage a screw 4| having a cylindrical head 42.

From the foregoing the operation of the device should now be readily understandable. Piston I8 is first moved to its lowermost position in its associated cylinder, or until the ends of wristpin 17 and their associated apertures in the piston wall are clear of the cylinder wall. Thescrew clamping lugs 20 and 2.1 to ether is then removed and the tool 2'5 placed in the position shown in Figure 2, that is, with flattened head 30 passed through aperture 22 and with s the ball-shaped head "42 of screw 4| seated in the upper portion" 'iust past the center of pressure, whereby it will remainin the position thus assumed, leaving both hands free for removal of wrist-pin l1 if necessary.' Screw 4| is provided :so that the pressure exerted to separate the :lugs may be varied by altering the effective length of the composite member-comprised of member 35 and screw M. Ellie, device may, of course, be made in a variety of shapes and sizes to accommodate any desired :typegor manufacture of cylinder, piston and connecting rod. I

a :From the foregoing it will now be seen that there is herein provided a tool accomplishing .all the objects of this invention and many others including advantages of great practical utility and-commercial importance.

As, many embodiments, may be made of this inventive concept, and'as many modifications may be made in the embodiment herein shown and described it is to be understood that all matter .hereinbefore set forth is to be interpreted merenot in a limiting sense.

.pivoted to said curved rod at an intermediate point, whereby pressure on one end of said curved rod will exert a leverage through said member on said end portion to separate said lugs.

2. In a tool for releasing the grip of a con necti-ngrod having projecting lugs with apertures therethrough, one of said apertures being threaded and the other being smooth and of greater diameter than said threaded aperture, on a Wristpin; the combination of a curved rod, an end portion of said rod being of a diameter sufficient to pass through said second aperture but not said first aperture, a member adapted to be seated on a portion of said connecting rod, pivoted to said curved rod at an intermediate point whereby pressure 'on one end of said curved rod will exert a leverage through said member on said end portion to separate said lugs, and means for varying the effective length of said member to vary the pressure exerted -on said lug having said threaded aperture therethrough.

3. In a tool for releasing the grip of :a .connecting rod clamp having projecting lugs with apertures therethrough, one of -said apertures being threaded and the other being smooth and of greater diameter than the threaded aperture, on a wrist-pin, the combination of a curved rod, an end portion of said rod being of a diameter suificient to pass through said second aperture but not said first aperture, a member having a threaded aperture in its lower extremity, a :screw rotatably engaged in said aperture to vary the effective length of said member, :a head on said screw adapted to be seated on a portion of said connecting rod, and a pivot securing said member to said curve-d rod at an intermediate point whereby pressure on one end of said curved .rod exerts a leverage through said member and said .head on said end portion to separate said lugs, EUGENE T. DAUBS. 

